Kilroy is the premier developer and operator of LEED properties in Southern California, and, with 25% of our office portfolio certified under LEED, we have emerged as a leader among public office REITs in LEED performance. Not only do we build all of our new development with the goal of LEED Goal and major renovation projects with the goal of LEED Silver, but we also undertake projects on the cutting edge of LEED.
We are one of the first developers in the nation to pursue certification under the LEED for Neighborhood Development rating system for our mixed-use project in San Diego. This project will feature compact development, infill site selection, energy and water efficient buildings, and a pedestrian-friendly design that will reduce automobile use. In addition, we developed the first LEED for Core & Shell project in San Diego, and are currently developing the first Core & Shell project under LEED 2009 in El Segundo.
In addition, we are currently pursuing LEED Silver for over 600,000 sq feet of office space, and have acquired nearly a million square feet of LEED Gold property in 2011 alone. We look forward to increasing our LEED portfolio percentage in the future through new development and through achieving LEED for Existing Buildings certification for properties in the existing portfolio.
To complement its commitment to LEED, Kilroy has committed all of its new development, renovations, facility alterations, and tenant improvements to extremely high materials purchasing standards. This includes the specification of low-VOC paints, coatings, adhesives and sealants, composite wood and agrifiber products that are free of urea formaldehyde, high-recycled content acoustical ceiling tile and drywall, and, where possible, FSC certified wood. We believe that these strict standards will increase the quality of the indoor air for our tenants and drive the market for sustainable products.
We are also proud members of the US Green Building Council.